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답안 #781292

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
781292 2023-07-13T02:06:13 Z joelgun14 The Xana coup (BOI21_xanadu) C++17
100 / 100
 53 ms 21324 KB 
#include <bits/stdc++.h>
using namespace std;
const int lim = 3e5 + 5;
bool on[lim], vis[lim];
vector<int> edges[lim];
long long dp[lim][2][2];
void dfs(int nd) {
    vis[nd] = 1;
    if(on[nd])
        dp[nd][1][0] = 1, dp[nd][0][1] = 0;
    else
        dp[nd][0][0] = 0, dp[nd][1][1] = 1;
    for(auto i : edges[nd]) {
        if(!vis[i]) {
            dfs(i);
            // case now not pressed
            // awalannya 0
            int x = dp[nd][0][0], y = dp[nd][0][1];
            dp[nd][0][0] = min(dp[i][0][0] + x, dp[i][1][0] + y);
            dp[nd][0][1] = min(dp[i][0][0] + y, dp[i][1][0] + x);
            // case now pressed
            // awalannya 1
            x = dp[nd][1][0], y = dp[nd][1][1];
            dp[nd][1][0] = min(dp[i][0][1] + x, dp[i][1][1] + y);
            dp[nd][1][1] = min(dp[i][0][1] + y, dp[i][1][1] + x);
        } 
    }
}
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    int n;
    cin >> n;
    for(int i = 0; i < n - 1; ++i) {
        int u, v;
        cin >> u >> v;
        edges[u].push_back(v);
        edges[v].push_back(u);
    }
    for(int i = 1; i <= n; ++i)
        cin >> on[i];
    for(int i = 1; i <= n; ++i) {
        for(int j = 0; j < 2; ++j)
            dp[i][j][0] = dp[i][j][1] = 1e6;
    }
    // dp on tree
    // cari dr child
    // pake dp[i][1], nandain dp di subtree ini dengan root 1 atau root 0
    // problem -> child bisa effect root
    // nanti ans itu dp[1][0]
    // nanti 4 kemungkinan
    // root 0, root changed
    // root 0, root not changed
    // root 1, root changed
    // root 1, root not changed
    // transisi dp?
    dfs(1);
    if(min(dp[1][1][0], dp[1][0][0]) > n) {
        cout << "impossible" << endl;
    }
    else
        cout << min(dp[1][1][0], dp[1][0][0]) << endl;
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 7252 KB Output is correct
2 Correct 4 ms 7252 KB Output is correct
3 Correct 3 ms 7252 KB Output is correct
4 Correct 3 ms 7252 KB Output is correct
5 Correct 3 ms 7252 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 7252 KB Output is correct
2 Correct 4 ms 7252 KB Output is correct
3 Correct 3 ms 7252 KB Output is correct
4 Correct 3 ms 7252 KB Output is correct
5 Correct 3 ms 7252 KB Output is correct
6 Correct 4 ms 7288 KB Output is correct
7 Correct 3 ms 7252 KB Output is correct
8 Correct 4 ms 7252 KB Output is correct
9 Correct 3 ms 7252 KB Output is correct
10 Correct 4 ms 7252 KB Output is correct
11 Correct 3 ms 7252 KB Output is correct
12 Correct 3 ms 7380 KB Output is correct
13 Correct 3 ms 7252 KB Output is correct
14 Correct 5 ms 7380 KB Output is correct
15 Correct 3 ms 7380 KB Output is correct
16 Correct 3 ms 7380 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 36 ms 19920 KB Output is correct
2 Correct 41 ms 19768 KB Output is correct
3 Correct 40 ms 19960 KB Output is correct

Subtask #4
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 41 ms 19960 KB Output is correct
2 Correct 42 ms 19824 KB Output is correct
3 Correct 42 ms 20000 KB Output is correct
4 Correct 38 ms 13140 KB Output is correct
5 Correct 39 ms 13764 KB Output is correct
6 Correct 40 ms 13948 KB Output is correct
7 Correct 5 ms 7380 KB Output is correct
8 Correct 14 ms 9900 KB Output is correct
9 Correct 38 ms 14976 KB Output is correct
10 Correct 37 ms 15180 KB Output is correct
11 Correct 47 ms 15444 KB Output is correct
12 Correct 50 ms 15692 KB Output is correct
13 Correct 36 ms 14664 KB Output is correct
14 Correct 40 ms 15128 KB Output is correct

Subtask #5
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 7252 KB Output is correct
2 Correct 4 ms 7252 KB Output is correct
3 Correct 3 ms 7252 KB Output is correct
4 Correct 3 ms 7252 KB Output is correct
5 Correct 3 ms 7252 KB Output is correct
6 Correct 4 ms 7288 KB Output is correct
7 Correct 3 ms 7252 KB Output is correct
8 Correct 4 ms 7252 KB Output is correct
9 Correct 3 ms 7252 KB Output is correct
10 Correct 4 ms 7252 KB Output is correct
11 Correct 3 ms 7252 KB Output is correct
12 Correct 3 ms 7380 KB Output is correct
13 Correct 3 ms 7252 KB Output is correct
14 Correct 5 ms 7380 KB Output is correct
15 Correct 3 ms 7380 KB Output is correct
16 Correct 3 ms 7380 KB Output is correct
17 Correct 36 ms 19920 KB Output is correct
18 Correct 41 ms 19768 KB Output is correct
19 Correct 40 ms 19960 KB Output is correct
20 Correct 41 ms 19960 KB Output is correct
21 Correct 42 ms 19824 KB Output is correct
22 Correct 42 ms 20000 KB Output is correct
23 Correct 38 ms 13140 KB Output is correct
24 Correct 39 ms 13764 KB Output is correct
25 Correct 40 ms 13948 KB Output is correct
26 Correct 5 ms 7380 KB Output is correct
27 Correct 14 ms 9900 KB Output is correct
28 Correct 38 ms 14976 KB Output is correct
29 Correct 37 ms 15180 KB Output is correct
30 Correct 47 ms 15444 KB Output is correct
31 Correct 50 ms 15692 KB Output is correct
32 Correct 36 ms 14664 KB Output is correct
33 Correct 40 ms 15128 KB Output is correct
34 Correct 3 ms 7380 KB Output is correct
35 Correct 3 ms 7252 KB Output is correct
36 Correct 3 ms 7380 KB Output is correct
37 Correct 3 ms 7252 KB Output is correct
38 Correct 4 ms 7404 KB Output is correct
39 Correct 4 ms 7380 KB Output is correct
40 Correct 5 ms 7368 KB Output is correct
41 Correct 3 ms 7380 KB Output is correct
42 Correct 4 ms 7376 KB Output is correct
43 Correct 3 ms 7380 KB Output is correct
44 Correct 4 ms 7380 KB Output is correct
45 Correct 36 ms 21308 KB Output is correct
46 Correct 38 ms 21164 KB Output is correct
47 Correct 39 ms 21324 KB Output is correct
48 Correct 36 ms 14336 KB Output is correct
49 Correct 36 ms 14916 KB Output is correct
50 Correct 36 ms 15088 KB Output is correct
51 Correct 3 ms 7380 KB Output is correct
52 Correct 14 ms 9964 KB Output is correct
53 Correct 43 ms 15100 KB Output is correct
54 Correct 39 ms 15232 KB Output is correct
55 Correct 36 ms 15436 KB Output is correct
56 Correct 48 ms 15744 KB Output is correct
57 Correct 35 ms 14676 KB Output is correct
58 Correct 35 ms 15076 KB Output is correct
59 Correct 13 ms 9940 KB Output is correct
60 Correct 33 ms 14304 KB Output is correct
61 Correct 36 ms 14976 KB Output is correct
62 Correct 53 ms 15236 KB Output is correct
63 Correct 38 ms 15228 KB Output is correct
64 Correct 39 ms 15216 KB Output is correct
65 Correct 39 ms 15640 KB Output is correct
66 Correct 32 ms 15652 KB Output is correct
67 Correct 33 ms 15528 KB Output is correct
68 Correct 31 ms 15496 KB Output is correct
69 Correct 32 ms 15556 KB Output is correct
70 Correct 35 ms 15476 KB Output is correct